The invention relates to a magnifying glass and to an illumination means.
Especially in medicine, for example in microsurgery, but also in other areas of medicine, magnifying glasses are known. These include telescopic spectacles or magnifying glasses mounted on a headband. Furthermore, illumination means are also known for these magnifying glasses, with which the respective viewing field or surgical field can be illuminated.
Light sources for these illumination means have recently been halogen lamps with the pertinent optics. The major disadvantages of these illumination means include high heat evolution, relatively large dimensions, and high electric power requirements for their operation so that either only stationary power supply devices with no mobility or battery-operated power supply units which can be carried on the body and are heavy can be used.
In particular, a binocular magnifying glass which can be worn with a headband with two magnifying optics and one illumination means (WO 96/25873) is known. It consists of a light source spatially separate from the magnifying glass and the illumination means there. The light from which source is coupled into the illumination means via an optical fiber. This known version has the problem that the optical fiber is disruptive when a binocular magnifying glass is being used and the freedom of movement of the user is adversely affected.
Furthermore, a binocular ophthalmoscope for viewing the retina of the human eye is also known (U.S. Pat. No. 5,841,509). To illuminate the retina there is a light source such as a light emitting diode, with light mixed into the beam path of the ophthalmoscope so that the illumination of the retina to be examined takes place by part of the optics of the ophthalmoscope. The light source is housed either directly in the housing of the ophthalmoscope or separate from it, the light in turn then being coupled via an optical fiber. To avoid damage to the retina, the light source has only very low power. This device is neither designed nor suited as a magnifying glass for viewing the working field or the surgical field.
The object of the invention is to avoid the problems of the prior art. To achieve this object, the magnifying glass is made and the illumination means is utilized.
One special feature of the invention is that the light source is formed by several LEDs with a high illumination intensity of at least 2000 mcd, for example with an illumination intensity of at least 3000 mcd. The light of the individual LEDs is focused at the focus by the focusing element which is assigned to the respective LED. The LEDs are supplied with power via a portable power supply unit located separately from the light source and connected to it via a power supply cable.
In one especially advantageous embodiment of the invention, there is an actuating element separate from the illumination means controlling the illumination means by contact or by proximity, especially turning it on and off. This is especially important in surgical applications with respect to hygiene and sterility to be maintained.